I am trying to call a custom method on my UITabBarController subclass from within one of the child view controllers. I have instantiated my CustomTabBarController class as the root view controller in AppDelegate.swift, however, the .tabBarController property on my child view controllers is of the class UITabBarController instead of CustomTabBarController.
Why does this happen? Is it possible to have the .tabBarController property on my view controllers reflect my subclass instead of the default UITabBarController class?
Here is my subclass:
import UIKit
class CustomTabBarController: UITabBarController, UITabBarControllerDelegate, LoginControllerDelegate {
let defaults = UserDefaults.standard
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
setupViews()
}
override func viewDidAppear(_ animated: Bool) {
checkLoginStatus()
}
func checkLoginStatus() {
if defaults.bool(forKey: "isLoggedIn") == false {
let loginController = LoginController()
loginController.delegate = self
present(loginController, animated: true, completion: nil)
}
}
func loginControllerDidDismiss() {
print("Delegation is working...")
}
func setupViews() {
let homeController = HomeController()
homeController.tabBarItem = CustomTabBarItem(title: "Home", imageNames: ["courthouse-icon-unselected", "courthouse-icon"])
let homeNavController = UINavigationController(rootViewController: homeController)
homeNavController.navigationBar.applyCustomStyle()
tabBar.tintColor = UIColor(red:0.18, green:0.34, blue:0.65, alpha:1.00)
self.setViewControllers([homeNavController], animated: true)
}
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
print(viewController.title)
return true
}
}
In my view controller, I would like to access this class like so:
import UIKit
class HomeController: ListController {
override func viewDidLoad() {
super.viewDidLoad()
self.title = "Home"
self.tabBarController??? // Right now this is a UITabBarController, but I would like to it be a CustomTabBarController
}
}
The best approach is to test whether it's what you believe it to be and cast it so that the compiler knows the correct class.
e.g.:
if let custom = self.tabBarController as? CustomTabBarController {
custom.checkLoginStatus()
} else {
print("Unexpected controller \(self.tabBarController)")
}
Related
I have been trying to refactor my source code so that it would conform to the Coordinator Pattern. I have used UITabBarController as the parent viewController of my app which contains 4 viewControllers.
I have been following the tutorials on how to implement the Coordinator pattern for iOS apps, and I have created and set up the protocols and classes of the Coordinator. I have a button inside my viewController (child viewController of the TabbarViewController), however, on button click, coordinator is not pushing / navigating to the desired VC, and I see the coordinator is returning nil on the debug console while debugging through the breakpoint, and I could not figure it out how to resolve this issue.
MainCoordinator.swift:
class MainCoordinator: SubCoordinator {
var subCoordinators = [SubCoordinator]()
var navigationController: UINavigationController
init(navigationController: UINavigationController) {
self.navigationController = navigationController
}
func start() {
print("Initialized.. .")
UIApplication.app().window?.rootViewController = self.navigationController
let vc = SplashViewController.instantiate()
vc.coordinator = self
navigationController.pushViewController(vc, animated: false)
}
}
// testing using a simple Viewcontroller class, its background color is set to red, so if the
// navigation works, a blank red VC should appear. but not working so far
func testView() {
let vc = ViewController.instantiate()
vc.coordinator = self
navigationController.pushViewController(vc, animated: false)
}
}
SubCoordinator.swift:
protocol SubCoordinator {
var subCoordinators: [SubCoordinator] { get set }
var navigationController: UINavigationController { get set }
func start()
}
StoryBoarded.swift:
protocol StoryBoarded {
static func instantiate() -> Self
}
// I am using storyBoard, and `instantiate()` should instantiate and return the specified VC
// from the Storyboard with the specified VC id (?)
extension StoryBoarded where Self: UIViewController {
static func instantiate() -> Self {
let id = String(describing: self)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
return storyboard.instantiateViewController(withIdentifier: id) as! Self
}
}
FirstViewController.Swift:
class FirstViewController: UIViewController, StoryBoarded {
#IBOutlet weak var button: UIButton!
var coordinator: MainCoordinator?
//MARK: - viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
// If uncommented the below line, coordinator is not returning `nil`, but not navigating
anyways!
//coordinator = MainCoordinator(navigationController: UINavigationController())
}
#IBAction func onButtonTap(_ sender: Any) {
// So, basically I would expect the coordinator to navigate to the testView, but not
navigating
coordinator?.testView()
}
}
ViewController.swift:
// testView
class ViewController: UIViewController, StoryBoarded {
var coordinator: MainCoordinator?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
self.view.backgroundColor = .red
}
}
and
// TabbarController, set as the root VC after the splashVC is completed
class MainViewController: UITabBarController, StoryBoarded {
var coordinator: MainCoordinator?
override func viewDidLoad() {
super.viewDidLoad()
let firstVC = UIStoryboard.firstViewController()
let secondVC = UIStoryboard.secondViewController()
let views: [UIViewController] = [firstVC, secondVC]
self.setViewControllers(views, animated: false)
self.navigationController?.navigationBar.isHidden = false
}
}
start() is being called, and splashVC appears and updates rootViewController with MainViewontroller on completion, But the navigation is not working at all on button click event.
Any feedback or help would highly be appreciated!
Since you're using the StoryBoarded protocol, you should follow the pattern and call instantiate() for initialization. Then, just set the coordinator.
class MainViewController: UITabBarController, StoryBoarded {
var coordinator: MainCoordinator?
override func viewDidLoad() {
super.viewDidLoad()
let firstVC = FirstViewController.instantiate()
let secondVC = SecondViewController.instantiate()
firstVC.coordinator = self.coordinator
secondVC.coordinator = self.coordinator
let views: [UIViewController] = [firstVC, secondVC]
self.setViewControllers(views, animated: false)
self.navigationController?.navigationBar.isHidden = false
}
}
I have a tabbar controller. When the user clicks on one of the tab bar buttons, I need to update a value in the UIPageViewController that is in the target view controller.
I am trying to use a delegate to inform a UIPageViewController which tab bar button was clicked:
protocol PlanTypeDelegate {
func setIntro(thisFlow planType: UITabBarItem)
}
class NewTabBarController: UITabBarController {
var planTypeDelegate : PlanTypeDelegate?
override func viewDidLoad() {
super.viewDidLoad()
// create and handle tab bar button actions
}
override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
planTypeDelegate?.setIntro(thisFlow: item)
}
In my UIPageController I have the following:
class IntroPageController: UIPageViewController {
override func viewDidLoad() {
super.viewDidLoad()
guard let tabbar = self.parent as? NewTabBarController() else { return }
tabbar.delegate = self
}
}
extension IntroPageController : PlanTypeDelegate {
func setIntro(thisFlow planType: UITabBarItem) {
print("this item:\(planType)")
}
}
Instead I get this error message:
I am new to passing data between VCs so I have no idea how to go about handling this scenario.
EDIT
Same error after update
You can Achieve it like this.. without Delegate ... write setIntro method in IntroPageController i hope it will solve your Issue
class NewTabBarController: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
}
}
func tabBarController(_ tabBarController: UITabBarController,
shouldSelect viewController: UIViewController) -> Bool{
if let controller = viewController as? IntroPageController {
controller.setIntro(thisFlow: tabBarController.tabBarItem)
}
return true
}
You can also achieve it through Protocol for that write... All controllers who confirm PlanTypeDelegate can perform action against this method
func tabBarController(_ tabBarController: UITabBarController,
shouldSelect viewController: UIViewController) -> Bool{
if let navController = viewController as? UINavigationController {
if let myViewController = navController.topViewController , let homeController = myViewController as? PlanTypeDelegate {
homeController.setIntro(thisFlow: tabBarController.tabBarItem)
}
} else if let controller = viewController as? PlanTypeDelegate {
controller.setIntro(thisFlow: tabBarController.tabBarItem)
}
return true
}
I'm trying to make custom transitions when pushing/popping viewControllers from a custom UINavigationController class. I'm implementing the UINavigationControllerDelegate method
navigationController(_:animationControllerFor:from:to:), but it does not get called.
I'm creating a UINavigationController in storyboard and putting it's class as CustomNavigationController. I'm also assigning it a root ViewController in the storyboard (let's call the root VC CustomViewControllerRoot).
Here is the code I'm using (simplified and not tested):
protocol NavigationDelegate {
func pushCustomViewController()
func popViewController()
}
class CustomNavigationController: UINavigationController, NavigationDelegate {
init() {
super.init(nibName: nil, bundle: nil)
delegate = self
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func viewDidLoad() {
self.navigationBar.isHidden = true
guard viewControllers.first is CustomViewControllerRoot else {fatalError("Error")}
rootVC = viewControllers.first as? CustomViewControllerRoot
rootVC?.navigationDelegate = self
//Setup the rest of the viewControllers that are to be used
customVC = CustomUIViewController()
customVC?.navigationDelegate = self
}
var rootVC: CustomViewControllerRoot?
var customVC: CustomViewController?
func pushCustomViewController() {
if customVC != nil {
self.pushViewController(customVC!, animated: true)
}
}
func popViewController() {
self.popViewController(animated: true)
}
}
extension CustomNavigationController: UINavigationControllerDelegate {
func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationController.Operation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
// This is never called, even though the delegate is set in the initializer to CustomNavigationController
print("TEST")
return nil
}
}
I then let each custom UIViewController subclass in my navigation hierarchy delegate push or pops to this CustomNavigationController above. For example this is the root vc assigned to the navigation controller. Since it lies as root it never needs to push itself or be popped, as it is presented when the CustomNavigationController is presented. It delegates to CustomNavigationController when it finds that another VC should be presented on top of it:
class CustomViewControllerRoot {
var navigationDelegate: NavigationDelegate?
override func viewDidLoad(){
super.viewDidLoad()
}
#objc func someButtonPressedToPresentCustomVC(){
navigationDelegate?.pushCustomViewController()
}
}
The dismissal is handled inside each CustomViewController which also delegates the pop down to the CustomNavigationController (I don't want to use the navbar for dismissal so there is no "back button" from the start):
class CustomViewController: UIViewController {
var navigationDelegate: NavigationDelegate?
override func viewDidLoad(){
super.viewDidLoad()
}
#objc func dismissViewController(){
navigationDelegate?.popViewController()
}
}
To my understanding the UINavigationControllerDelegate method inside the extension of CustomNavigationController should be called whenever a push or pop is performed since I'm setting the delegate variable to self in the initializer?
Your navigation controller should have a root view controller.
And then you should push custom view controller from your root view controller. And delegate method calls
Navigation Controller Code:import UIKit
class CustomNV: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
delegate = self
}
}
extension CustomNV: UINavigationControllerDelegate {
func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationController.Operation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
print("TEST")
return nil
}
}
RootViewController code:
class RootViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
let viewController = UIViewController(nibName: nil, bundle: nil)
viewController.view.backgroundColor = .green
navigationController?.pushViewController(viewController, animated: true)
}
}
Set root view controller as root for navigation controller in storyboard
I write the following code inside the function and call that into viewWillAppear method.
I want to disable to Tabbar Bottom items access.
Here TabarVC() is TabBarView controller class name.
let tabbar = TabarVC()
tabbar.tabBar.isUserInteractionEnabled = false
class OneViewController: UIViewController ,UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.tabBarController?.delegate = self
}
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
if viewController.isKind(of: twoViewController.self as AnyClass) {
return true
}
if viewController.isKind(of: threeViewController.self as AnyClass) {
return false
}
}
}
This question has been asked before and has been answered, my question is not unique but there must be something missing. I'm simply trying to check if user logged in to app before as his data stored in UserDefaults but it doesn't work for me, this is the class of my TabBarViewController
class TabViewController: UITabBarController, UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
}
// UITabBarDelegate
override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
print("Selected item")
}
// UITabBarControllerDelegate
func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
if(viewController is MessagesViewController) {
print("trueee")
if(UserStorage.id == "") {
Toast.toast(messsage: "not loggoed user", view: self.view)
}
} else {
print("faaaaaaaalse")
}
print("Selected view controller")
}
}
i want to check if user open MessageViewController then if user is logged in to print something but it always print faaaaaaaalse
note: Toast.toast() is a function i created to show toast
and UserStorage.id returns user id stored in USerDefaults
this is image which shows my structure:
what should I do ?
Just your tab bar’s root controllers are 2 navigaton controllers, not MessageViewController. Firstly with tabBarController you have to find navigationController which contains your MessageViewController than in this navigation find the needed ViewController.
So I have the solution for you:
import UIKit
class TabbarController: UITabBarController, UITabBarControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
// for tab bar initialization
if let viewControllers = self.viewControllers,
viewControllers.count >= 1,
// the index of viewController is 0 here, but if your tab bar's started controller is not 0 you can set yours
let navigationController = viewControllers[0] as? UINavigationController {
for controller in navigationController.viewControllers {
if let messagesViewController = controller as? MessagesViewController {
doWithMessagesViewControllerWhatYouWant(_viewController: messagesViewController)
}
}
}
}
// UITabBarControllerDelegate
func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
if let navigationController = viewController as? UINavigationController{
for controller in navigationController.viewControllers {
if let messagesViewController = controller as? MessagesViewController {
doWithMessagesViewControllerWhatYouWant(_viewController: messagesViewController)
}
}
}
}
private func doWithMessagesViewControllerWhatYouWant(_viewController: MessagesViewController) {
print("do some operations with messagesViewController")
if(UserStorage.id == "") {
Toast.toast(messsage: "not loggoed user", view: self.view)
}
}
}